code shows error in function

I am using following code to write text file.. This is the part of a function.. and it works...

 fid = fopen(sprintf('Image%d.txt',imageNumber),'wt');

 for j=1:length(y),

    fprintf(fid,'%f %f\n',y(j),x(j));

 end

Now when i am using following code to read the same file then it shows error..

why.?

 C = textscan('Image%d.txt',imageNumber);

Answer 1

[Walter Roberson]

You do not textscan() a file name: you textscan() a file identifier created by fopen()

fid = fopen(sprintf('Image%d.txt',imageNumber),'rt');
C = textscan(fid, '%f%f');
fclose(fid)